Internal-combustion engine



W. B, CROFTON.

INTERNAL COMBUSTION ENGINE.

APPLICATION FILED MAY 22, 1918.

1 3%8fi93; Patented Aug 3, H26

: entree stares caram QFFICE.

WILFRED rnnnnron cnorron, or YnoviLLn, JOI-IANNESBURG, sourn a I AFRICA.

INTERNAL-COMBUSTION ENGINE.

Specification of Letters Patent.

Patented. Aug. 3, 1920.

Application filed May 22, 1918. Serial No. 236,017.

To aZZ whom it may concern.

Be it known that I, lVILrnnn Bnnnn'ron CnorroN, a subject of the King of Great Britain, residing at 56 Harley street, Yeoville, Johannesburg, Transvaal Province of the Union of South Africa, have invented certain new and useful Improvements in Internal-Combustion Engines, of which the following is a specification.

The present invention hasreference to in ternal combustion engines, particularly four-stroke engines. The purpose of the invention is-to provide novel means for increasing the amount of gas passed through the engine, with the object of increasing the power of the engine without change of fuel, or of enabling low grade fuel, such as carbon monoxid, to be used, or of maintaining the power of the engine in spite of lowered atmospheric pressure. The invention is here described as an attachment for existing engines of the motor car type. In the accompanying drawings-- Figure I is a vertical section of the attachment and I Fig. II shows a four-cylinder four-stroke internal combustion engine fitted with the invention. r y

A, A A A indicate the engine cylinders. r

V The induction valves 1 and exhaust valves 2 of said engine are left for operation in the usualmanner; but it, is necessary that the induction valves should not remain open after the completion of the induction stroke of their respective pistons. 3 indicates the carbureter and 4 the induction manifold feeding the fourcylinders.

5 is a compressor cylinder which is shown as screwed in place of one of the valve caps. One such cylinder 5 is fitted to each engine cylinder. In the cylinder 5 is fitted the piston 6. 7 The lower end of the cylinder 5 is in direct connnunication'with the engine cylinder so that the face 7 of the piston 6 is acted upon by the explosionin the engine cylinder.

8 is a connection bywhich gas is conveyed from the manifold 4 to each of the compressor cylinders 5. Its opening to each cylinder 5 is controlled by a separate nonreturn valve 9 opening toward the cylinder 5. The connection 8 is usually fitted with a throttle valve 10. I

An outlet connection llijoins each cylinder 5 to another engine cylinder; and it may be secured to the engine cylinder in place the cylinder and steadied by a rod 16. Moreover when the piston is lifted a partial vacuum is created in the space 17 beneath the piston 6, which assists to return the piston. A small flow of air is allowedto and from this space 17 by means of a cook 18. This providessufiicient air to form a cushion to deaden the shockof stopping the return of the piston 6 and also prevents accum-ulation of air which would destroy the vacuum. The degree of the latter and consequently the resistance of the upward stroke of the piston may be varied byopening or closing the cooks 18, bymeans of'a common rod 19. i

' The delivery connection 11 from each cyl-,

'inder 5 is taken to the next firing cylinder of the engine. That is to say, in the example shown, the compressorcylinder 5 of engine cylinder A delivers to engine cylinder A that ofrcylinder A to A that of cylinder A to A and that of cylinder A tocylinder A.

The operationis as follows: At each explosion in an engine cylinder, the corresponding piston 6 is forced upward, andupon the subsequent fall of pressure in the engine oylinderis forced downward again. In so moving down it draws into its cylinder 5 a charge of gas from the.

induction pipe & and connection 8. At the next explosion in its eigine cylinder, this charge is ejected from the cylinder 5 into the next firing cylinder, say A This cylinder A has already made its induction stroke and drawn in, directly from the induction pipe 4, a charge of gas at rather below at: mospheric pressure; and its induction valve 1 has closed.

The additional charge from the compressor cylinder 5 is thus added to the ordinary induced charge. The augmented charge is thereupon compressed by the upstroke of the piston 20 in cylinder A and is fired and exhausted in the usual Way.

The result is that the pressure at the cominencement and termination o1 the working stroke of the engine is raised and the power of the engine is increased. In the case of a car engine which is not ordinarily required to develop its full power and using petrol, of which economy is a desideratum, the conipressors would be cut out of action during the ordinary running of the engine. This may be accomplishedby so adjusting the resist ance of the springs 14: and the vacuum in the space 17 that the piston 6 would not be lifted by the pressure developed by the explosion in the engine cylinder. Upon the engine throttle being further opened, without sub stantial increase of engine speed, the piston 6 bcomes operative and the power of the engine is immediately increased considerably, since the injection oi the increased charge increases the pressure of the explosion and so reacts further to increase the injection up to the limit which the apparatus is capable of. When however the engine is running at high speed, theengine piston 20 offers less resistance to the explosion and there is a consequent tendency for the compressors to become inoperative. The control of the operation of the compressors may however be eitfected manually by closing the throttle 10 to render them inoperative and opening said throttleto render them operative,

On the other hand, when using cheap low grade fuel, economy of which is not important, or which does not produce high explosive pressure, but which requires high compression for ignition, the compressor pistons are arranged to operate the whole time.

Again in the case of an aeronautical engine it is desirable to be able to maintain the volumetric elficiencyof the engine cylinder in spite of decreased density of the atmosphere at a height, with this object the compressor cylinders may be cut out at the beginningof a flight by the throttle 10 and brought into operation by gradually opening said throttle as greater altitudes are reached.

Having now particularly described and ascertained thenature of my said invention and in what manner the same is to be performed I declare that what I claim is 1. In combination with a multi-cylinder four-stroke. internal combustion engine, a compressor device having a piston exposed to the explosion in an engine cylinder and thereby driven on its working stroke, said compressor drawing gas from a suitable source such as the engine inlet manifold, and delivering its charge to another engine cylinder to be compressed for ignition therein. 7

2. Apparatus as claimed in claim 1 in which the connection'is such that the compressor charge is admitted to the engine cylinder after the induction stroke in the latter.

3. Apparatus as claimed in claim 1, in which the compressor cylinder is fitted with a single piston one end of which is exposed to the explosion and the other endof which operates as a compressor piston.

t. A compressor attachment for an internal combustion engine, comprising a cylinv der, a piston therein having. oneface adapted to be acted upon by explosion in the engine and the other face servmg as a compressor piston, means tending to'torce the piston WILFRED BRERETON c rorrou. 

